Self servo writing file using the widest head

Abstract

A self servo writing file and method for writing servo patterns in a direct access storage device are provided. First servo information is written on a data storage media at a first crash stop. The transducer heads are moved offset from the written servo information while reading the last written servo information until the detected servo signal equals a predetermined value. Then servo information is written on the data storage media responsive to the detected servo signal equal to the predetermined value. The moving and writing steps are sequentially repeated until a second crash stop is reached. A quad-burst servo amplitude pattern or phase pattern can be used for the servo information. The servo writing method is adapted easily for many different servo options. When the file uses a hybrid servo or sector servo, the other surfaces can be written by duplicating the servo bursts with a high bandwidth servo system of the file. Alternatively, the servo writing steps can be repeated for each of the other surfaces for providing head dependent pitch. Variable track pitch can be provided by selectively varying the predetermined value compared with the detected servo signal.

What is claimed and desired to be secured by Letters Patent of the United States is: 
     
       1. A method for writing servo patterns in a direct access storage device including a plurality of data storage media mounted for simultaneous rotation about an axis and an actuator for moving each of a plurality of transducer means relative to an associated data storage media for reading and writing data to the associated data storage media, said method comprising the steps of: utilizing each of said plurality of transducer means and writing a data pattern to respective data storage media;   identifying one of said plurality of transducer means having a widest head; and   saving said identified transducer means having said widest head as a reference head for writing servo patterns to said data storage media.   
     
     
       2. A method for writing servo patterns in a direct access storage device as recited in claim 1 wherein said step of identifying one of said plurality of transducer means having a widest head includes the steps of: selecting one of said plurality of transducer means and moving said selected one of said plurality of transducer means by a selected offset. 
     
     
       3. A method for writing servo patterns in a direct access storage device as recited in claim 2 includes the steps of measuring and saving an original amplitude of each of said plurality of transducer means and measuring and saving an offset amplitude of each of said plurality of transducer means. 
     
     
       4. A method for writing servo patterns in a direct access storage device as recited in claim 3 includes the steps of comparing each said offset amplitude with said original amplitude of each of said plurality of transducer means. 
     
     
       5. A method for writing servo patterns in a direct access storage device as recited in claim 4 includes the steps of identifying one of said plurality of transducer means having a maximum ratio to identify said one of said plurality of transducer means having a widest head. 
     
     
       6. A method for writing servo patterns in a direct access storage device as recited in claim 1 wherein said step of saving said identified transducer means having said widest head for referencing the writing servo patterns to said data storage media includes the step of referencing a written pitch of the written servo patterns to said widest head. 
     
     
       7. A method for writing servo patterns in a direct access storage device as recited in claim 1 wherein said step of saving said identified transducer means having said widest head for referencing the writing servo patterns to said data storage media includes the step of selecting said identified transducer means having said widest head as a reference head for writing servo patterns to said data storage media. 
     
     
       8. A self servo writing file comprising: a plurality of data storage media mounted for simultaneous rotation about an axis;   an actuator for moving each of a plurality of transducer means relative to an associated data storage media for reading and writing data to the associated data storage media,   means for writing a data pattern to respective data storage media utilizing each of said plurality of transducer means;   means for identifying one of said plurality of transducer means having a widest head; and   means for saving said identified transducer means having said widest head as a reference head for writing servo patterns to said data storage media.   
     
     
       9. A self servo writing file as recited in claim 8 further includes a housing containing said plurality of data storage media and said plurality of transducer means. 
     
     
       10. A self servo writing file as recited in claim 9 wherein said means for saving said identified transducer means having said widest head for referencing the writing servo patterns to said data storage media includes means for referencing a written pitch of the written servo patterns to said widest head. 
     
     
       11. A self servo writing file as recited in claim 10 wherein said means for saving said identified transducer means having said widest head for referencing the writing servo patterns to said data storage media includes means for selecting said identified transducer means having said widest head as a reference head for writing servo patterns to said data storage media. 
     
     
       12. A self servo writing file as recited in claim 8 wherein said means for identifying said one of said plurality of transducer means having a widest head includes means for measuring and saving an original amplitude of each of said plurality of transducer means and means for moving and for measuring and saving an offset amplitude of each of said plurality of transducer means. 
     
     
       13. A self servo writing file as recited in claim 12 further includes means for identifying one of said plurality of transducer means having a maximum ratio of said original amplitude and said offset amplitude to identify said one of said plurality of transducer means having a widest head.